Centrifugal vapor-liquid separator

ABSTRACT

A centrifugal vapor-liquid separator is formed by a vertically extending riser pipe closed at its upper end and laterally enclosed by a collecting shell so that a collecting space laterally surrounds the riser pipe. An impeller provided with two sets of separate passageways and located at the upper end of the riser pipe flows the vapor-liquid mixture from the riser pipe through one set of passageways into the collecting space and gives it a swirling motion. The liquid and vapor separate in the collecting space with the separated liquid exiting from the space either upwardly or downwardly along the inside wall of the shell. Vapor carried over into the collecting space below the impeller flows out through the other set of passageways extending upwardly through the impeller into a vapor discharge pipe located above the upper end of the riser pipe.

[ June 11, 1974 United States Patent Meier et al.

[ CENTRIFUGAL VAPOR-LIQUID SEPARATOR Primary Examiner-Bernard Nozick [75] Inventors: Fran Meier, Oberhausen-Sterkrade; gg Agent Firm Toren McGeady and Erich Ossendorf, Bochum; Hubert Inger Wolfgarten, Oberhausemsterkrade, all of Germany Assignee: Gutehoffnungshuette Sterkrade ABSTRACT oberhausemsterkrad'e, A centrifugal vapor-liquid separator is formed by a Germany vertically extending riser pipe closed at its upper end and laterally enclosed by a collecting shell so that a [22] Filed: Sept- 1973 collecting space laterally surrounds the riser pipe. An ['21] separate passagepper end of the riser pipe xture from the riser pipe impeller provided with two sets of ways and located at the u Appl. No.: 401,549

Related US. Application Data flows the vapor-liquid mi [63] Continuation I971 -in-part of Ser. No. 134,227,.April 15, through one set of passageways into the collecting abandoned space and gives it a swirling motion. The liquid and imm p pm Ia s v m CH mwwh h ..n .n mm w afl 0. 0c sw m ga S .mw d .m hmd H S mm.m Ga l m m te m m n mo enlll t mdwfl Dhwm mm r w ni Pwwn a, a v mdc d 14 0 5 M 5 H 5 .5 8. 3 u 3 a e 5 H 5 mm m .mur. "n3 H I" C WM .w UhF T a 555 [56] References Cited UNITED STATES PATENTS .re VA emhm fim a w w mw 9n i ar Pew o aw 5 8 e e v m m h em m mm h t o a o im l m me an. i u D. 0. s g W ri O M m rn m lewd riser pipe.

1,784,627 12/1930 Hamill 55/455 FOREIGN PATENTS OR APPLICATIONS 2 Claims, 4 Drawing Figures CENTRIFUGAL VAPOR-LIQUID SEPARATOR This is a 'Continuation-In-Part of co-pending Application Ser. No. 134,227; filed Apr. 15, 1971 now abandoned.

SUMMARY OF THE INVENTION The present invention is directed to a centrifugal vaper-liquid separator including a riser pipe connected to an annular collecting space through a bladed impeller and, more particularly, it concerns the formation of separate sets of passageways through the impeller for providing separate flow paths through the impeller.

In vapor-liquid separators where the vapor-liquid mixture is conveyed from a riser tube through an impeller into a surrounding collection space, the impeller imparts a rotary or swirling motion to the mixture. The liquid portion of the mixture is directed outwardly against the wall of the collecting shell rotating in a parabolic course and draining downwardly along the wall. In this process, the vaporportion of the mixture is carried along in the downward direction with the liquid portion. To prevent the separated vapor portion, as it rises upwardly within the collecting shell, from interfering with the separating action of the vapor-liquid mix ture passing through the impeller and also to avoid any obstacle in the path of the upwardly flowing vapor portion, a known device has been used, such as disclosed in German Design Pat. No. 6,602,623, which provides tubes for the passage of the vapor portionupwardly through the impeller. This known arrangement, however, has the disadvantage that it causes a certain pressure loss in the vapor portion or in the vapor-liquid mixture. Accordingly, it is the primary object of the present invention to provide an impeller arrangement which affords a reduction in the pressure losses previously experienced and improves the efficiency of the separator. Further, another object of the invention is the simplification of the construction of the vaporliquid separator.

Therefore, in accordance with the present invention, the structure of the impeller is arranged to form two sets of laterally closed, open ended passageways having the axes of one set extending transversely of the axes of the other set so that one set of passageways conveys the vapor-liquid portion through the impeller, while the other set flows separated vapor upwardly through the impeller.

In a preferred arrangement of the present invention, pairs of interconnected blades forming the vapor flow passageways are spaced apart by at least one freestanding or separate blade and the free-standing or separate blade or blades in combination with the adjacent interconnected blades form the vapor-liquid passageways through the impeller.

In accordance with the present invention, the total cross sectional flow area for the passage of separated vapor through the impeller is enlarged without any appreciable change in the flow cross section of the vaporliquid mixture channels through the impeller. Furthermore, the vapor-liquid separator can be constructed with a smaller height and at the same output. This characteristic makes it possible for the separator to be conveniently assembled and disassembled through a manhole.

Further, the'present construction affords a drainage pipe extending through the upper closed end of the riser pipe and connecting a vapor discharge pipe above the riser pipe with the space enclosed by the collective shell about the impeller at a location below the impeller. With this arrangement any liquid which has been carried along by the vapor and separates out in the vapor discharge pipe, is led through the drainage pipe downwardly into the collecting shell while maintaining the liquid out of contact with the vapor-liquid mixture flowing upwardly through the riser pipe.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosurc. For a better understanding of the invention, its operating advantages and specific objects. attained by its use. reference should be had to the accompanying drawings and descriptive matter in' which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING FIG. 3 is a perspective view from above of the impel" ler shown in FIG. 2; and

FIG. 4 is a perspective view from below of the impeller in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION In the drawing. a centrifugal vapor-liquid separator S is shown in which a vapor-liquid mixture from the vaporizing zone of a steam generator is conducted upwardly through an upright riser pipe 1. The upper end of the riser pipe 1 is closed by a sheet metal plate 2 and an impeller 3 extends laterally about and projects out wardly from the circumference of the riser pipe at its upper end.

Aligned above the riser pipe 1 and connected to the radially outer edge of the upper side of the impeller 3 is a vapor discharge pipe 5. At its lower end 50, the vapor discharge pipe 5 has a frusto-conical shape and it tapers inwardly as it extends upwardly from the impeller. The upper end'5b of the vapor discharge pipe is cylindrically shaped.

Laterally enclosing both the riser pipe I and the vapor discharge pipe Sis a vertically arranged collecting shell 6 which has its upper end 611 spaced upwardly above the impeller and its lower end 6b spaced downwardly from the impeller. The collecting shell 6 is spaced outwardly from the radial outer side of the impeller, as well as from the riser pipe and the vapor discharge pipe so that it defines the radially outer boundary of a continuous upwardly extending annular space composed of a lower space 60 located about the riser pipe below the impeller, an intermediate space 6d radially outward from the impeller and an upper space 62 about the vapor discharge pipe above the impeller. At its lower end the collecting shell is equipped witha siphon closure 7. At the upper end of the collecting shell 6 a sheet metal deflector 8 is attached at spaced locations 8a to the outer surface of the collecting shell below its upper edge and then extends from the'points of attachment spaced outwardly from the outer surface of the collecting shell to a point closely above the upper end 6a of the shell where it has a narrow rounded section 8b, which extends inwardly over and is spaced from the upper edge of the shell. Between the locations 8a, openings are formed so that a liquid can pass between the outside surface of the collecting shell and the deflector. As shown in FIGS. 2, 3 and 4, the impeller is an annular shaped member, though when viewed in H6. 3 it appears to be closed at its top surface because of the plate 2. The impeller is made up of an annular horizontally arranged top plate 3a, an annular horizontally arranged bottom plate 3b, a plurality of laterally spaced blades 9, extending between the top plate and the bottom plate and also extending in the radial direction 'of the riser from the inner to the outer edges of the plates, panels 9a connect the radially inner edges of the blades 9 and panels% connect the radially outer edges of the same blades The blades are arranged so that one blade 10 is positioned between adjacent pairs of blades 9, or in other words the blades 9 and 10 are arranged in a continuous pattern of two blades 9 and one blade 10 around the annular impeller.

From the drawing, it can be noted that the impeller constitutes two sets of passageways, the first passageways 19 formed between adjacent blades 9 and the second passageways formed between the blade 10 and the adjacent blades 9. The pattern of the passageways around the impeller is such that there is one first passageway, two second passageways, one first passageway, two second passageways, and so on. The top plate 3a and the bottom plate 3b have openings aligned with the first passageways 19 so that the first passageways extend upwardly through the impeller while the top and bottom plates close off the upper and lower sides of the second passageways 20 so that these passageways extend in a radial direction, that is, normally to the direction of the first passageways. ln FIGS. 3 and 4 the arrangement of the first and second passageways through the impeller are clearly illustrated.

As is shown in FIG. l, the sheet metal plate 2 which provides the closure for the riser pipe has a shallow inverted cone shape forming a collection dish at the lower end of the vapor discharge pipe 5. Extending downwardly from the low point of the sheet metal plate is a drainage pipe 11 which passes first through the riser pipe 1 at a point spaced inwardly from the impeller and then at a point below the impeller it is bent outwardly and passes angularly downwardly through the wall of the riser pipe into the lower space 60 formed about the riser pipe by the collecting shell.

In operation, the vapor-liquid mixture from the steam generator passes upwardly through the riser pipe and since continued upward flow is blocked by the plate 2, it changes direction and passes radially outwardly through the second passageways 20 in the impeller 3 and enters the intermediate space 6d of the annular space defined by the shell 6. The curved shape of the blades 9 and 10 in the impeller impart a rotary or swirling motion to the vapor-liquid mixture passing through the second passageways and due to centrifugal force the liquid portion of the mixture is thrown against the inside wall of the collecting space so that it flows in a parabolic course in the annular space. A part of the liquid portion rises upwardly along the inside wall of the collecting shell and is discharged directly to the exterior of the separator by means of the deflector 8, that is, it flows to the upper end 6a of the collecting shell where it passes'between the deflector and the shell exiting through the openings' c. The vapor separated from the liquid in the upper space 6e flows out through the open upper end of the collecting shell. The remaining part of the liquid portion passes downwardly along the inside wall of the collecting shell and is discharged through the siphon closure 7. However. the arrangement of the siphon closure prevents any possible discharge of vapor from the lower end of the collecting shell.

While one part of the vapor separated from the liquid flows from the separator through the open upper end of the collecting shell, another part ofthe vapor portion is carried along by the liquid portion into the lower space 6c of the annular space formed between the riser pipe and the collecting shell below the impeller and from that location it passes upwardly through the first passageways l9 and above the impeller enters into the lower end 5a of the vapor discharge pipe 5. Accordingly, the vapor portion flowing upwardly through the first passageways 19 does not interfere with the flow of the vapor liquid mixture radially outwardly through the second pasageways 20 and an efficient arrangement of the separator is afforded. Any liquid portion of the mixture which is carried by the vapor through the first passageways into the vapor discharge pipe 5 separates out by gravity and flow downwardly onto the upper surface of the plate 2, and then is removed by the drainage pipe 11 into the lower space 6c below the impeller. With this arrangement, the separated liquid from the vapor discharge pipe 5 does not contact the vapor-liquid mixture flowing upwardly through the riser pipe 1. The sepa rated vapor flowing up through the vapor discharge pipe 5 exits from its open upper end.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

l. A centrifugal vapor liquid separator comprising an upwardly extending riser pipe for conducting a vaporliquid mixture in the upward direction, means forming a closure for the upper end of said riser pipe, a collecting shell laterally enclosing and spacedoutwardly from said riser pipe and extending upwardly above and downwardly below the upper end of the said riser pipe and forming an annular space about said riser pipe, an impeller located at the upper end of said riser pipe below said closure means and forming outlet passageways for the vapor-liquid mixture passing upwardly through said riser pipe into the annular space between said collecting shell and said riser pipe, said impeller having a plurality of blades oriented radially outwardly from said riser pipe for directing the vapor-liquid mixture from the upper end of said riser pipe outwardly into the space between said riser pipe and said collecting shell, a vapor discharge pipe located above said riser pipe and arranged in communication with the upper side of said impeller, said impeller forming upwardly directed passageways communicating between the space below said impeller which is located between. the outer surface of said riser pipe and'the inner surface of said collecting shell and said vapor discharge pipe, wherein the improvement comprises that said plurality of blades comprises first blades and second blades, said first blades arranged in laterally spaced side-by-side relationship at least in pairs, with each pair of said blades forming a first passageway therebetween and said second blades interspersed between said first blades, so that at least one said second blade is located between adjacent pairs of said first blades and the at least one said second blade and the juxtaposed surfaces of said first blades in the adjacent pairs of said first blades form therebetween second passageways, said impeller includes first wall means and second wall means, with said first wall means oriented upwardly and extending between the radially inner edges and between the radially outer edges of each pair of said first blades forming the first passageways so that the first passageways are closed on the radially inner and outer sides of said impeller and are open on the upper and lower surfaces of said impeller, and said second wall means are oriented transversely of the upward direction and extend between the upper edges between the lower edges of said first and second blades forming the second passageways so that the second passegways are closed on the upper and lower sides of said impeller and are opened at the radially inner and outer sides and form the outlet passageways for conducting vapor-liquid mixture from said riser pipe into the space within said collecting shell outwardly from said impeller and said first passageways forming the upwardly directed passageways connecting the space below saidimpeller between said riser pipe and said collecting shell with said vapor discharge pipe so that vapor can flow upwardly through said impeller into said vapor discharge pipe without interfering with the flow of vapor-liquid mixture passing through the second passageways.

2. A centrifugal vapor-liquid separator, as set forth in claim 1, wherein a drainage pipe is connected at its upper end to said means forming the closure for the upper end of said riser pipe and is arranged in communication with said discharge pipe, said drainage pipe extending downwardly from the closure from the upper end of said riser pipe through said riser pipe spaced inwardly from said impeller and at a location below said impeller, said drainage pipe passes outwardly through said riser pipe and communicates with the space between said collection shell and said riser pipe below said impeller.

UNITED STATES PATENT OFFICE (TER i HFRI/VH6 W CQRRECTION lnn-ni, MU. 3131'5'359 H muted i n L974 lnvcntorha) Meier et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Heading of the Patent:

The first name of inventor Meier should read:

--Franz-.

Signed and sealed this 1st day of October 197a.

(SEAL) Attest:

MCCOY M. GIBSON JR. C, MARSHALL DANN Attesting Officer Commissioner of Patents F ORM PO-1050 (10-69) USCOMM- DC 60376-P69 u.s GOVERNMENT PRINTING OFFICE: I969 0-355-31". 

1. A centrifugal vapor-liquid separator comprising an upwardly extending riser pipe for conducting a vapor-liquid mixture in the upward direction, means forming a closure for the upper end of said riser pipe, a collecting shell laterally enclosing and spaced outwardly from said riser pipe and extending upwardly above and downwardly below the upper end of the said riser pipe and forming an annular space about said riser pipe, an impeller located at the upper end of said riser pipe below said closure means and forming outlet passageways for the vapor-liquid mixture passing upwardly through said riser pipe into the annular space between said collecting shell and said riser pipe, said impeller having a plurality of blades oriented radially outwardly from said riser pipe for directing the vapor-liquid mixture from the upper end of said riser pipe outwardly into the space between said riser pipe and said collecting shell, a vapor discharge pipe located above said riser pipe and arranged in communication with the upper side of said impeller, said impeller forming upwardly directed passageways communicating between the space below said impeller which is located between the outer surface of said riser pipe and the inner surface of said collecting shell and said vapor discharge pipe, wherein the improvement comprises that said plurality of blades comprises first blades and second blades, said first blades arranged in laterally spaced side-by-side relationship at least in pairs, with each pair of said blades forming a first passageway therebetween and said second blades interspersed between said first blades, so that at least one said second blade is located between adjacent pairs of said first blades and the at least one said second blade and the juxtaposed surfaces of said first blades in the adjacent pairs of said first blades form therebetween second passageways, said impeller includes first wall means and second wall means, with said first wall means oriented upwardly and extending between the radially inner edges and between the radially outer edges of each pair of said first blades forming the first passageways so that the first passageways are closed on the radially inner and outer sides of said impeller and are open on the upper and lower surfaces of said impeller, and said second wall means are oriented transversely of the upward direction and extend between the upper edges between the lower edges of said first and second blades forming the second passageways so that the second passegways are closed on the upper and lower sides of said impeller and are opened at the radially inner and outer sides and form the outlet passageways for conducting vapor-liquid mixture from said riser pipe into the space within said collecting shell outwardly from said impeller and said first passageways forming the upwardly directed passageways connecting the space below said impeller between said riser pipe and said collecting shell with said vapor discharge pipe so that vapor can flow upwardly through said impeller into said vapor discharge pipe without interfering with the flow of vapor-liquid mixture passing through the second passageways.
 2. A centrifugal vapor-liquid separator, as set forth in claim 1, wherein a drainage pipe is connected at its upper end to said means forming the closure for the upper end of said riser pipe and is arranged in communication with said discharge pipe, said drainage pipe extending downwardly from the closure from the upper end of said riser pipe through said riser pipe spaced inwardly from said impeller and at a location below said impeller, said drainage pipe passes outwardly through said riser pipe and communicates with the space between said collection shell and said riser pipe below said impeller. 